1. Field of the Invention
This invention relates in general to a method and apparatus for forming and closing display packages from a card blank having a window opening in an overlying plastic sheet thereon which includes means for forming a pocket of the plastic sheet, filling the pocket with an article, folding the card to close the pocket and subsequently sealing the pocket with the card.
2. Description of the Prior Art
At the present time, there are many types of machines for forming and filling display packages. In one known type, a rotatable carrier table for a card blank is positioned in sequence into association with apparatus for heating and forming a pocket, filling the formed pocket, closing the formed pocket by folding the blank carrying the pocket at a fixed station and, thereafter, moving the folded and closed blank into association with sealing means for sealing it closed. A disadvantage in the known machine structure is that the table carrier for the card must be indexed and stopped at each of a multitude of stations at which an operation is carried out. This necessarily means that the driving mechanism for the carrier must be such that it permits indexing motion and stopping of the carrier for each operation. The known drive mechanisms which are operable thus require, for example, a separate station heating the plastic sheet and also for forming a pocket in the heated sheet as well as separate stations for sealing the package and for subsequently removing it from the machine. Therefore, such a machine must be of very large size and require a great amount of time in passing the card through operational paths and stopping them at each location in order to effect the formation and filling of the display card pocket. Attempts have been made to construct machines of this character which will operate at extremely high speeds but all of them require a stopping of the operation while the individual package forming apparatus operate on a card blank and plastic sheet. The disadvantage in the known constructions is that not only the heating and forming operations and sealing operations are performed at separate fixed stations, but also, the auxiliary operation of folding is carried out while the machine is temporarily stopped. The reason for this is that the known devices for automating the machine completely so that it operates continuously as the formations are made are very expensive to manufacture and difficult to operate.